Tamil Layout Requirements

W3C Group Draft Note

More details about this document
This version:
https://www.w3.org/TR/2024/DNOTE-ilreq-taml-20240724/
Latest published version:
https://www.w3.org/TR/ilreq-taml/
Latest editor's draft:
https://w3c.github.io/iip/tamil/
History:
https://www.w3.org/standards/history/ilreq-taml/
Commit history
Editor:
(W3C)
Feedback:
GitHub w3c/iip (pull requests, new issue, open issues)

Abstract

This document describes or points to requirements for the layout and presentation of text in languages that use the Tamil script. The target audience is developers of Web standards and technologies, such as HTML, CSS, Mobile Web, Digital Publications, and Unicode, as well as implementers of web browsers, ebook readers, and other applications that need to render Tamil text.

Status of This Document

This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.

This document describes the basic requirements for Tamil script layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and digital publications about how to support users of Tamil script languages. Currently the document focuses on the Tamil script as used for Tamil. The information here is developed in conjunction with a document that summarises gaps in support on the Web for Tamil.

🚩
This document is a stub awaiting future edits. .
See Tamil Script Resources instead.

The editor's draft of this document is being developed by the India Language Layout Task Force, part of the W3C Internationalization Interest Group. It is published by the Internationalization Working Group. The end target for this document is a Working Group Note.

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This document was published by the Internationalization Working Group as a Group Draft Note using the Note track.

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This document is governed by the 03 November 2023 W3C Process Document.

1. Introduction

1.1 About this document

The aim of this document is to describe the basic requirements for Tamil script layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and digital publications, and for application developers, about how to support users of the Tamil script. The document currently focuses on texts using the Tamil language.

2. Tamil Script Overview

The Tamil script is an abugida, ie. consonants carry an inherent vowel sound that is overridden using vowel signs or killed using a virama.

The Tamil script is written horizontally, left to right. Words are separated by spaces.

There are fewer consonants than in other Indic scripts. Tamil has no aspirated consonant letters, and symbols are allocated on a phonemic basis, rather than phonetic. This means that , for example, may be pronounced as the allophones k ɡ x ɣ or h, according to where it appears relative to other sounds in a word, but its pronunciation doesn't change the word.

The consonant letters used for pure Tamil words are supplemented by Grantha consonant signs which are used for English and Sanskrit loan words. Repertoire extensions for non-native sounds are achieved by preceding a consonant with U+0B83 TAMIL SIGN VISARGA (āytam).

Consonant clusters are indicated using the visible puḷḷi dot (the virama) to indicate that no vowel follows a consonant. Exceptions to the rule are 2 ligated forms: க்ஷ kʃʌ and ஶ்ரீ ʃri.

Word-initial clusters do not appear in Tamil. Syllable-/word-final consonants are just written using ordinary consonants with the puḷḷi overhead, eg. தமிழ் t̪amiɻ Tamil.

The Tamil orthography has an inherent vowel, and represents vowels using vowel signs, including pre-base glyphs and circumgraphs. All circumgraphs can be decomposed. All vowel signs are combining marks, and are stored after the base character.

There are also independent vowels, one for each vowel sound, including the inherent vowel, and these are used to write all standalone vowel sounds.

The only composite vowels are those created by decomposition of the circumgraphs, and involve 2 glyphs, one on each side of the base consonant(s).

Tamil is diglossic: the classic form is preferred for writing and public speaking, and is mostly standard across the Tamil-speaking regions; the colloquial, spoken form differs widely from the written.

There can also be differences in letter shapes and other typographic approaches between the Tamil used in India and that used in places like Singapore and Malaysia (and even Sri Lanka).

The script has no upper-/lowercase distinction.

A. Change log

B. References

B.1 Informative references

[i18n-glossary]
Internationalization Glossary. Richard Ishida; Addison Phillips. W3C. 22 April 2024. W3C Working Group Note. URL: https://www.w3.org/TR/i18n-glossary/